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Thursday, November 30, 2017

Saving species -- I don't want to "get over it"

A recent opinion piece in the Washington Post, "Species die. Get over it." by R. Alexander Pyron, has a lot of people talking. In this article, Dr. Pyron states that we are in a mass extinction period (often called the Anthropocene), but it's not really something we need to worry about. He states:

Species have always gone extinct; it's part of evolution,

humans have always caused extinctions and there's nothing morally wrong with that, and

humans can come up with technological fixes for any damage we cause.

I've written many times about specific endangered species, endangered species management and conservation, success stories, and misconceptions. As these posts demonstrate, I heartily disagree with Dr. Pyron's statement that human-caused extinction isn't morally wrong. Yes, humans have always impacted species, sometimes causing extinction, but we've never caused extinctions at the rate we see today. Where Dr. Pyron really went astray was when he started talking about evolution and extinction. While it's true that species do go extinct due to natural selection and evolution, that background rate of extinctions is estimated at 10-25 species worldwide per year. Currently, the rate is estimated at 100 to 1000 species worldwide per year. Thus the rate of extinction is currently 10 to 100 times what we would expect from natural selection and evolution.

Dr. Pyron also states that species will either evolve or disappear in response to human pressure. He seems to forget that evolution is not a process measured in decades or even centuries. Evolution occurs over thousands and tens of thousands of years for most species. Evolutionary change is not what we are seeing in response to the pressure put on other species by humans during the last 200 to 300 years. We are seeing the complete annihilation of species, because there is no time for populations to adapt. Did we see complete annihilation in the past? Yes, but usually this destruction was done on a population level, not at a species level. Populations are local groups of individuals of one species. Sometimes, due to a changing environment, populations will be extirpated, but other populations of the species remain and evolve. What we're seeing currently is the loss of entire species, rather than isolated populations.

Finally, Dr. Pyron states that we'll be fine without the species we lose -- we can "technology" our way out of the problem. To paraphrase James Comey, "Oh Lordy I hope you're right," but I don't think you are. First off, we don't understand the natural world well enough to be able to control it. Second, biodiversity tells us about our environment -- species are indicators of our environmental health. If a skunk, orchid, crane, or frog can't survive in this environment, what makes us think we can?

So what's the plan? I disagree with Dr. Pyron that we should "get over it." Rather, we should adopt the "precautionary principle" which states that we should avoid actions unless we're sure that they will not lead to future harm. Species conservation, from habitat protection to last-ditch efforts at captive breeding, is a necessary step to ensure a healthy planet for future generations.